The present invention relates filler neck closure caps, and particularly to caps for closing filler necks of vehicle fuel tanks. More particularly, the present invention relates to a filler neck cap that provides a lost-motion driving connection between a handle and a closure member to delay actuation of the closure member in a cap-removal direction during cap removal and provides a visual indication that the fuel cap has been advanced to the fully closed position, sealing the vehicle fuel tank during cap installation.
Conventional fuel caps for closing threaded filler necks of vehicle fuel tanks generally include an outer handle or shell that is coupled for rotation to a closure member or housing and a sealing ring for establishing a seal between the cap and the filler neck. The housing is normally formed to include threads that are configured to engage corresponding threads formed on the filler neck.
It is known to provide a torque override driving connection between the handle and the housing to prevent overtightening of the housing within the filler neck and to prevent possible scuffing or other damage to the filler neck sealing ring in the cap during installation of the cap on the filler neck. For example, U.S. Pat. No. 4,280,346 to Evans shows a torque override cap. It is also known to provide either a direct driving connection or delayed actuation driving connection between the handle and the housing. For example, U.S. Pat. No. 4,765,505 to Harris shows a delayed actuation driving connection fuel cap.
In addition, it is known to provide a visual indication that the cap has been advanced to the fully closed position for caps without mechanisms for lost-motion connections or torque override driving connections. For example, U.S. Pat. No. 4,436,219 to Reutter shows a sealing cap that displays a visual indicator when the sealing cap is fully closed.
It is perceived, however, that some users occasionally do not properly install their fuel cap in a vehicle fuel tank filler neck, resulting in excessive evaporative emissions. One solution to this problem would be to simplify the installation method, such as with an easy-on one-quarter turn fuel cap. Another solution is to provide a fuel cap with a delayed actuation driving connection that includes a visual indication that the fuel cap has been advanced to the fully closed position. This visual indication can also be accompanied by an audible click and a noticeable change of feel when the handle is turned after the fuel cap has been advanced to the fully closed position. What is needed is a lost-motion filler neck cap having a mechanism that is operable to provide a user with tactile and visual signals that the cap has been properly installed in a sealed filler neck-closing position and is compatible with a torque override system in the cap for preventing damage to a filler neck sealing ring during installation of the cap in the filler neck.
According to the present invention, a cap is provided for use in a filler neck. The cap includes a closure or housing for closing the filler neck, a handle for rotating the closure relative to the filler neck, a delayed action device for providing a lost-motion driving connection between the handle and closure, a torque override device for preventing damage to the filler neck sealing ring due to overtightening of the housing during installation of the cap on the filler neck, and an indicator for signalling that the fuel cap has been advanced to the fully closed position.
In preferred embodiments, the torque override system provides a direct connection between the handle and the closure in the counterclockwise cap-removal direction and a torque override driving connection in the clockwise cap-advancing direction. The system includes a ring positioned between the handle and the closure and resilient annular fingers on the closure that terminate in pawl teeth. The side of the ring adjacent to the closure includes spaced-apart teeth. The faces of the pawl teeth and the spaced-apart teeth are configured to provide a direct connection in the cap-removal direction and a torque override connection in the cap-advancing direction.
The ring is also integral to the lost-motion driving connection. This feature disables the connection between the handle and the closure when the handle is rotated from the fully closed position to the cap-removal position, thus maintaining the seal between the cap and the filler neck when the handle is unintentionally rotated in the cap-removal direction. The lost-motion driving connection mechanism includes drive lugs that are coupled to the handle and driven lugs that are attached to the ring. The drive lugs engage the driven lugs to transmit rotation from the handle to the closure. The spacings of the drive lugs and the driven lugs result in the lost-motion driving connection and establish the amount of lost-motion achieved.
The ring and the handle rotate independently except for when the cap is in the cap-removal orientation and the handle is being rotated in the cap-removal direction, and when the filler neck is sealed and the torque override system is engaged. A visual indication that the filler neck is sealed is provided by placing an indicator dot on the ring and including an indicator window in the handle so that the indicator dot is visible through the indicator window when the filler neck is sealed and the torque override system is engaged.
Additional objects, features, and advantages of the invention will become apparent to those skilled in the art upon consideration of the following detailed description of a preferred embodiment exemplifying the best mode of carrying out the invention as presently perceived.